Middlesbrough captain Grant Leadbitter played 90 minutes for the club's under-23 side on Friday night during a 2-2 with West Brom.
The 32-year-old midfielder has played just two games in the Championship for Tony Pulis' side this campaign, and hasn't been in the squad for a league fixture since August.
Leadbitter, who joined Boro in 2012, could return to the first team for Tuesday's Carabao Cup quarter-final against Burton, after playing every minute in the previous four rounds.
Sunderland owner Stewart Donald admitted in the summer that Leadbitter was on the Black Cats' radar, however it's unclear whether they will reconsider a deal with the player's wages a potential stumbling block.
Leadbitter started his career at Sunderland and played over 100 games for the Black Cats before moving to Ipswich in 2009.
Meanwhile, a date for Boro's third-round FA Cup tie at home to Peterborough has been confirmed.
The game will take place on Saturday January 5 (3pm kick-off).
Tickets for the fixture will go on sale from Friday December 21 at 9.30am.
Boro season card holders have until 4pm on Friday December 28 to guarantee their usual seat and buy at a discounted price.
Posh overcame fellow League One side Bradford to reach the third round on penalties, following a thrilling 4-4 draw at Valley Parade.
Forward George Miller, who is on loan from Boro, scored twice for Bradford in the second-round replay, but it wasn't enough to send the Bantams through.
Another Boro striker, Tyrone O'Neill, came on for the final 12 minutes as Hartlepool beat Leamington 1-0 in the FA Trophy.
Aynsley Pears and Luke Armstrong, on loan at Gateshead, didn't feature at the weekend after The Heed's FA Trophy clash with Salford City postponed due to a frozen pitch.